SELECTION OF ORGANIC PHASES FOR OPTIMAL STABILITY AND EFFICIENCY OF FLAT-SHEET SUPPORTED LIQUID MEMBRANES

The efficiency and the stability of flat-sheet supported liquid membranes (SLMs) were studied in the case of the active transport of an amino acid, L-valine. Independent measurements on the organic phase (valine distribution, water concentration and viscosity) combined with the determination of some surface properties (interfacial tension and drop point) permit the description and prediction of the experimental permeability and stability of SLMs. The lifetime of the SLM was explained by taking into account diluent solubility in the aqueous phase, water concentration in the organic phase, interfacial tension between organic and feed phases, and drop point of the SLM. The experimental efficiency could be modeled by a mathematical expression involving the distribution coefficient of the solute and the viscosity of the organic solution.